The present invention relates to an image processing apparatus, an image processing method, a program of the image processing method, and a recording medium recording the program of the image processing method. The present invention can be applied to, for example, a resolution transformation. In the present invention, edge-enhancement processing and smoothing processing are performed in an edge-gradient direction having a largest gradient of a pixel value and an edge direction orthogonal to the edge-gradient direction, respectively, in order to improve image quality. Also, the edge-gradient direction and the edge direction are detected by different characteristics, the edge-enhancement processing and the smoothing processing are performed for each characteristic, and then the processing result of each characteristic is integrated. Thus, the loss of high frequency components and the occurrence of jaggy are prevented in order to reliably improve the image quality.
To date, in image processing, a resolution has been transformed, for example by linear interpolation processing, bicubic transformation processing. For example, Japanese Unexamined Patent Application Publication No. 2003-224715 has proposed a method of performing such image processing by a simple configuration.
However, in such image processing, there has been a problem in that jaggy occurs in edge portions, and if the characteristic for the linear interpolation processing and the characteristic of bicubic transformation processing are set so as to hide the jaggy, high frequency components are lost from that image to make the image lacking sharpness and blurred. In this regard, such blurring in an image is remarkable in a texture portion, and thus the characteristic of such processing is considered to be changed in the texture portion. However, in this case, a sense of dissimilarity and a flicker occur at the portion changing those characteristics.